Copyright
of all photographs belongs to the photographer/author who has taken/created
the photograph and may not be used without permission from that person.

For
images permission in accordance with the copyright/licensing/legal use
guidelines please e-mail us.

I
- Morphology Synopsis ( some meristic characters )

Total absolute lenght

Adult
male : 39 a 56.4 mm

Adult
female : 59 a 71 mm

Dorsal fin rays : / 10 ( 12 )

Caudal
fin rays : / 20 ( 22 )

Scales
on lateral line : 25 ( 26 )

Head
lenght body lenght ratio ( male ) : 0,19

Head
lenght body lenght ratio ( female ) : 0,23

II - Habitat and Geographical distribution

Variegated
Platy wild populations can be found from Southern Tamaulipas State to
Northern Vera Cruz State in Mexico.

Due
to its location as well as orography, this region is under an interesting
climate typology broad range.

Inside
the species geographical distribution, it’s possible to find tropical
humid to sub-humid classic weather at coastal areas and temperate from
sub-humid to draw in higher altitudes.

Mountain
edges and pronounced slope terrains limit the species abundance due to water
running flow.

Larger
rain fall period take place in summer and from June to October hurricanes
can occur.

Xiphophorus
variatus
can be found in rivers, streams and rivulets. While warmest surface of
running water is one of preferred environments, we can also locate many
populations in lentic surroundings like swamps, lakes and lagoons.

In
all wild biotopes these fishes show an evident preference for dense under
water vegetation proximity and as a rule they form schools in the vicinity
of shore, mainly composed by young and fry.

Adults
are more assiduous in deeper background, despite the fact that they remain
more often close to 50 cm or less.

In
other human made introduction new locations of this specie in some countries
throughout the world, we can find establish populations on the same kind of
surroundings. In temperate or cooler regions some introduced populations
seek refuge from lower temperatures, during winter months, in thermal
habitats, avoiding this way an assured fatality by cold narcosis.

Temperature annual maintenance for this species in captivity ( suggestion
) :

Thermal
regime (1)

Thermal
regime (2)

15ºC
( 59.0ºF )

17ºC
( 62.6ºF )

17ºC
( 62.6ºF )

19ºC
( 66.2ºF )

19ºC
( 66.2ºF )

21ºC
( 69.8ºF )

21ºC
( 69.8ºF )

23ºC
( 73.4ºF )

23ºC
( 73.4ºF )

24ºC
( 75.2ºF )

24ºC
( 75.2ºF )

25ºC
( 77.0ºF )

25ºC
( 77.0ºF )

26ºC
( 78.8ºF )

26ºC
( 78.8ºF )

28ºC
( 82.4ºF )

25ºC
( 77.0ºF )

26ºC
( 78.8ºF )

24ºC
( 75.2ºF )

25ºC
( 77.0ºF )

22ºC
( 71.6ºF )

23ºC
( 73.4ºF )

19ºC
( 66.2ºF )

20ºC
( 68.0ºF )

Each
one of this table lines report a different month period.

The temperature values are provided only as a reference for captivity
maintenance.

Performing
on this way your action can be considered reasonable, according with
the species known thermal exigencies.

It
is sometimes difficult, if not even impossible, to recreate in
aquarium the natural conditions, most favourable for the fish
biology. The most ideal situation was, if you could be able to
provide your fish a daily as well as a weekly temperature variation,
like in the wild.

For better understanding about perfect environment or to simulate
water temperature annual evolution according to natural habitat for
this species, please be so kind and have a look to Tampico and Veracruz
and graphics at
Wild water's temperatures ( all year round ) issue.

This
interesting diversity found in wild males can eventually be related to
genetic polymorphism or even social mechanisms.

In
fact, under some circumstances and specific conditions, young male’s
maturity can experience a deferral when larger adult ones are present in the
group. This process can even lead to sexual mature inhibition for a quite
notable period when pressure is high.

In
larger populations this delay can be minimum or inexistent. On these
generously proportioned communities another phenomenon can take place;
synchronized male’s sexual maturation.

There
is a genetically secluded relation between age and size for maturity on each
male. Individual progression right the way through this important and
decisive biological stage of live is however, by this fact, much correlated
with personal heritage. Like in many other species on this family, male’s
growth stops or reduces significantly after maturity, so details like these
aren’t difficult to determine.

According
to several scientific works, improved reproductive success is achievable by
larger males. Lower sized ones get some accomplishment by sneaky mating
procedures getting females by surprise, while larger competitors frequently
make use of exhibition rituals prior to copulation.

Apparently
females of this specie do care and accept by far more generously
proportioned partners.

You
can add also milled row, fish or molluscs from about all kinds used on human
diet.

Back
in nature, these fishes are gregarious and form schools with both sex
animals of different ages together under a structured hierarchy.

Females
spend most time foraging, while males dedicate a great deal of their time to
demonstrations, some fights but predominantly to attempt mating.

In
some places groups can attain large numbers, although usually is more common
to come across with 30 to 40 adults ( 7 to 10 males and 25 to 35 females ),
surrounded by an indistinct amount of immature fishes in different stages of
development. These groups are in evidence not far from shore, when best
protection and food abundance can provide them a good choice to carry on and
to face predation.

These
kinds of behaviour or interactions are quite adulterated in aquarium, due to
space limitations, artificial habitat availability, number of own specie
members present, predation absence and interactions with other species
included on each specific tank community.

Outdoors
garden pond groups however can return to an embryonic natural behaviour,
sometimes very close to the wild ancestrally. This will take place in
particular if certain habitat conditions are taken in consideration.

Cannibalistic
behaviour on newly birth fry is common according more than one testimony. As
we can expect in restrained spaces like in smaller thanks, without proper
vegetation cover to provide shelter and mainly when adults are inadequately
feed, this will be in fact common.

By
early 1920’s it starts to become evident that crosses inside Xiphophorus
genus were quite undemanding. What was new by the time that hobbyists get in
contact with the first hybrids was the impressive number of combinations
that could originate fertile offspring as well as progeny from both sexes.

These
occurrences are so usual that is even advisable to keep these species apart
and never let them cohabit in the “ small “ space of a domestic tank.

Cross
births include generally both parental species perceptible contributions and
intermediate bodily appearance is typical.

By
the above-mentioned facts, these F1 hybrids and their descendants do allow
that some sort of distinctions from one, or from both parental species, can
be genetically fixed with no trouble. In some special situations, a number
of characteristics from one of the two progenitors arise more strongly than
never at these hybrid descendants.

That
is the case of melanoma, one of the most deadly health disorders, commonly
known as the skin cancer. So evident was this happenstance that starts do
earn particularly scientist’s attention in USA and Germany since little
after of first crosses.

These
fish melanoma is some how related to melanic marks very common in certain
strains and among some hybrids in particular.

As
we could expect, such prevalence of the disease on these extraordinary small
lab partners, soon develop into a quite obvious talented work filed for
scientists at cancer investigation.

Since
than, some models have become popular, and these species in particular turn
out to be extremely useful instruments on the study of melanoma mechanisms
and progression.

An
incredible coincidence is that, remarkably, fish pigmented cells vulnerable
to the disease are morphologically, physiologically and in biochemical terms,
quite similar to human cells.

Investigation
methodology used with Xiphophorus
also include radiations, providing scientists a perspective about how this
kind of cancer evolutes as well as it incidence.

Right
the way through subsequent genealogy of laboratory manipulated fishes;
investigations can expose a great deal of melanoma progress from generation
to generation by means of genetic anticipation.

Next
time youpay attention to your aquarium inhabitant’s of this genus,please don’t forget their relative’s important role at cancer
hereditarily study.

VI - Threats,protection
and present status

Environment
contamination by domestic and industrial wastewater dumping in to nature,
aquatic resources use above levels that precipitation can re-establish for
agriculture, industrial or human consumption, as exotic species introduction
are the great threats that Xiphophorus variatus is facing at present
in some locations of wild distribution.

The
specie conservation status is not an issue for concerning at the moment and
it is not in the I.U.C.N. Red
List.

memorandum
about the Xiphophorus Genus : Regarding more or less 29 species
placed on it, 1 ( Xiphophorus
clemenciae ) is classified as data deficient, also
1 ( Xiphophorus couchianus ) is classified as critically
endangered and 2 (
Xiphophorus gordoni and Xiphophorus meyeri )
are classified as endangered.

We
should be extremely gratified and thank you in advance if some one
could provide new data about this topic, or even eventually any
correction to be made on this document.For
this purpose please be so kind and write us.

Copyright - Data and information authored and produced on this
website are in the public domain.

While
the content is in the public domain, some
pages contain images and material that are
copyrighted by others and used here with
permission.

Such
information is available for private use,
study or research. You should obtain
permission from the copyright owner for
other uses. Please carefully examine all the
content and all linked pages for copyright
restrictions and to secure the necessary
permissions.

Content
accuracy and usability of data and
information - Every
effort is made to provide and maintain
accurate, complete, useable, and timely
information on this website. However, some
data and information accessed through these
web pages may, of necessity, be presented
prior to final review and confirmation.

These
data and information are provided with the
understanding that they are not guaranteed
to be correct or complete. Users are
cautioned to consider carefully the
provisional nature of these data and
information before using them; such data and
information are the singular responsibility
of the user.